add comment on how to use config

Author: jhunsaker

doc/example-nginx-figment.conf

@@ -1,3 +1,6 @@
+# replace YOUR_AUTH_TOKEN_HERE
+# docker run -v /path/to/nginx-figment.conf:/etc/nginx/nginx.conf:ro -p 7899:7899 -p 7900:7900 -d docker.io/nginx
+
 worker_processes 1;
 
 events {}